Heat exchanger



Dec. 10, 1929. I w J HOFFMANN 1,738,706

HEAT EX'CHANGER Filed Aug. '7, 1926 INVENTOR I ATTORNEY Patented Dec. 16 @929 WILLIAM J. HoFFMAnn, or BROOKLYN, NEW YORK HEAT EXGHANGER Application filed August 7, 1926. serial .No. 127,829.

This invention relates to an apparatus for I and a method of heat exchangin'g,yas well as for improvements in the design and construction of such apparatus.

The invention is particularly adaptable to heat exchangers in which are employed continuous carriers as, for example, cooling conveyors for commodities such as candies, confections, biscuits, cakes, etc. The invention comprises a new and simple method ofplacing such a continuous carrier in direct contact with the heat exchanging devices and avoiding the use of separate pipes, tanks,

pans, brine or other agencies.

exchanging mechanisms for either heating or cooling purposes, but I have in this specification described my invention as applied to refrigeration, although it may be readily seen that it can be utilized for heating purposes.

One of the obJects of th1s inventlon 1s to provide means so that the continuous carrier of material to be cooled is in constant contact 7 of cooling surfaces to which tubes or pipes are intimately joined so as to increase the heat transmitting properties, and procure a.

maximum amount of refrigeration.

The invention further comprises means for reducing the cross-sectional area of the cooling tunnel through which passes the conveyor, and thus cause the more rapid circula tion of air and consequent cooling by con vection. The material carried on the conveyors may be readily chilled without resorting to forced air circulation.

Another object is to provide a cooling surface which is entirely covered and yet separated from the adjoining heat exchangers by a heat insulating substance or air space.

The improved device presents means for cooling material rapidly and to a low temperature and in a limited amount of space. It is simple, practical and economical of construction.

In the drawings:

The invention maybe employed in heat- Fig. 1 is anIelevation of a conveyor adapted to travel through a cooling tunnel.

Fig. 2 is a section along lines 22 of Fig. 1. Fig. 8 is a section along lines 33of Fig. 2. Surmounting the packing table 1, Fig. 1, is a conveyor 2, which passes through the cooling tunnel 3. The cooling tunnel 3 is provided with suitable air vents 4, as well as with pan 5 and drains 6. 1 In the tunnel .3 the conveyor2 passes di-' rectly over the cooling surface or plate 7. Integral with the cooling plate are the heat exchanging tubes or pipes 8, which in av coolingmechanism carry a refrigerating agent, such as brine, ammonia, water, etc., andthese V exchangers are welded, brazed or otherwise connected to the cooling surface 7 so as to increase the heat transmitting properties and extract.therefromk a maximum amount of heat. .The edges of the conveyor 2 are car-.

suitablyspaced away from the cooling plate v7, so as to allow an air space 10 between the edgesofthe conveyor and the'sup'ports 9.

' In the tunnel 3 are also provided laterally placed'temperature exchangers 11, which are suitably welded or brazed-tothe plates 12, and the, plates 12 are so situated that there are air spaces l3'between' the supports!) and the bottom of plate 12. In this construction itwill be noticed that any splashing or moisture'from the exchangers 11 will be depositedon the outside of plates 12 and drip down to'pan 5 and be carried away by the drain 6. Should there, however, be any deposit of moisture on the inside'of plate 12, such'moisture would i fall down through the air space 18, and thus flow into the drain 6, similarly with the exchangers 8,and thus it will be seen that the elimination of any sweating is provided for,

and that such moisture be eliminated from the horizontal cooling surface 7.. I

' The efficiency of the apparatus is further increased by the use of aninternal area and volume reducing sectionl t, which maybe suitably placed in the tunnel 3. I have shown such a section in Fig. 2 asbeing held by projections 15 resting on the outer and upper part of the tunnel walls 16. This section may be of any convenient size and removable, if

, ried. on non-metallicsupports 9, which are [14,determine the rapidity of air circulation.

"8, as shown in Fig. 3.

cooled by plate 7 and 'th'at'suchcooling is so desired. Insertion of the section in tunnel 3 decreases the cross-sectional area and thereby causes a rapid circulation of a1r by convection and assists 1n chllling the material carried on the conveyor. If it is desired, forced air circulation may be used, but I have found that by adjusting the side and location of the section 14 as well as the exchangers 11, I can eliminate the'useof forced air circulation and procure satisfactory results. The walls of the tunnel 3 may be insulated as at 17, so as to provide against loss of refrigeration.

The exchangers 11 are welded or brazed as shown at 18, F ig.,3, along the sides of the plate 12, thus minimizing losses due to air spaces or pockets, and the lengths of such 1 exchanger pipes connected by suitableimeans, such as ']o1nts.'19.. A similar construction 19 employed in connection W1th theexchangers It willbe noticed that the material resting upon the conveyor 2 is continuously being accentuat'edby the use of plates 12. This degree o'f're'frigeration can be increased by enlarging the cross-sectional area of the section 14, alnd decreased by lessening thesame. The location of exchangers 11 in relation to exchangers 8, as well as the size of the section about the conveyor 2, and thusthe degree of refrigeration may be altered as desired. The

" useofadditional tanks,-orpans, containing water, brine'and otherrefrigerating agents,

'as no'w"commonly employed, is entirelyeliminated."

It'will benoted that, as shown in Fig. 2,

the'hdrizont'al cooling surface '7 is covered conveyor 2 andthe horizontal cooling surface is separatedfrom the adjoining sides gust, 1926.

ture changers comprising plates separately constructedso'as to-permit moisture thereof to drip free of the carrier. I V

4. In aheat'ex'ch'anger the combination of a. carrier, lateral temperature changer and a horizontal temperature cha'1l;r ,"er "over which the carrier passes, saitl'horizontal temperature changer being. separated from said lateral temperature changers, said temperature changers comprislng plates separately constructed-so as to permit moisture thereof.

to drip free of'the carrier, and means for causing a rapid air circulation and limiting the'space in which" said air circulation takes place. I v p v,

.In witness jwhe'reojf, I have signed my name to this specification this 5' day of Au- Wrnnra ynoFFMa-NN.

"b the heatjinsulatingsubstance 9, as well as the'airspajcelO, so that sweating of the not restrictive.

cooling surface 7 is eliminated.

It is understood that the foregoing description of my invention, whilst explanatory, is It should be understood that departures may be made from the exact structures and arrangements therein shown and described without departing from the prin ciples of the invention and without sacrificing its chief advantages, and I claim all the ly co'me within'the principles of myinven- 't'ion and'the scope of my claims.

'I'cla'im: a 1. In a heat'ezichanger the combination of a carrienlateral temperature'cha-ngers, and

.a horizontal temperature changer over which the carrier passes, said horizontal temperature changer being separated from said lateral temperaturechangers.

"2. In a heat exchangerthe combinationof 1 a carrier, lateral temperature changers and a horizontal temperature changer over which changes in the specification which legitimatelzo 

